The invention relates to a hypodermic syringe comprising a hypodermic needle which can be extended from a needle space from a readiness position by a force storage means into an operative position. In particular the invention concerns a hypodermic syringe with a closed container which is arranged beside the needle space and which includes an injection material chamber and which receives a hypodermic liquid which can be put under pressure by a loadable pressure piston, wherein the hypodermic needle which has a needle duct is connected in the operative position to the injection material chamber.
Disposable syringes are known in which the needle must be screwed onto the syringe in order to put it into a condition in which it is capable of operation. The hypodermic liquid is taken from ampoules and is drawn up into the syringe. Manipulation with syringes of that kind is not satisfactory from the hygiene point of view, and is also time-consuming.
U.S. Pat. No. 4,556,100 discloses a syringe in which the hypodermic needle and the hypodermic liquid are disposed in a common space or chamber. The need is pushed out of the space under the pressure of a coil spring and at the same time the liquid is urged through a needle cannula. That arrangement suffers on the one hand from a disadvantage that the needle and the liquid are in constant contact with each other, in which case corrosion phenomena in respect of the needle due to the often corrosive liquids or impurities in the liquid cannot be excluded. In addition, in any case the liquid is also exposed with the needle so that it is not possible firstly to introduce the needle for example into the muscle tissue of a patient and then provide for delivery of the liquid.
The hypodermic syringe, in accordance with U.S. Pat. No. 4,384,579, was able to provide remedies in that respect.